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src/share/vm/prims/jniFastGetField.hpp@710a3c8b516e (annotated)
src/share/vm/prims/jniFastGetField.hpp
Tue, 08 Aug 2017 15:57:29 +0800
- author
- aoqi
- date
- Tue, 08 Aug 2017 15:57:29 +0800
- changeset 6876
- 710a3c8b516e
- parent 2314
- f95d63e2154a
- parent 0
- f90c822e73f8
- permissions
- -rw-r--r--
merge
| aoqi@0 | 1 | /* |
| aoqi@0 | 2 | * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved. |
| aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| aoqi@0 | 4 | * |
| aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
| aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
| aoqi@0 | 7 | * published by the Free Software Foundation. |
| aoqi@0 | 8 | * |
| aoqi@0 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| aoqi@0 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| aoqi@0 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| aoqi@0 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
| aoqi@0 | 13 | * accompanied this code). |
| aoqi@0 | 14 | * |
| aoqi@0 | 15 | * You should have received a copy of the GNU General Public License version |
| aoqi@0 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
| aoqi@0 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| aoqi@0 | 18 | * |
| aoqi@0 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| aoqi@0 | 20 | * or visit www.oracle.com if you need additional information or have any |
| aoqi@0 | 21 | * questions. |
| aoqi@0 | 22 | * |
| aoqi@0 | 23 | */ |
| aoqi@0 | 24 | |
| aoqi@0 | 25 | #ifndef SHARE_VM_PRIMS_JNIFASTGETFIELD_HPP |
| aoqi@0 | 26 | #define SHARE_VM_PRIMS_JNIFASTGETFIELD_HPP |
| aoqi@0 | 27 | |
| aoqi@0 | 28 | #include "memory/allocation.hpp" |
| aoqi@0 | 29 | #include "prims/jvm_misc.hpp" |
| aoqi@0 | 30 | |
| aoqi@0 | 31 | // Basic logic of a fast version of jni_Get<Primitive>Field: |
| aoqi@0 | 32 | // |
| aoqi@0 | 33 | // (See safepoint.hpp for a description of _safepoint_counter) |
| aoqi@0 | 34 | // |
| aoqi@0 | 35 | // load _safepoint_counter into old_counter |
| aoqi@0 | 36 | // IF old_counter is odd THEN |
| aoqi@0 | 37 | // a safepoint is going on, return jni_GetXXXField |
| aoqi@0 | 38 | // ELSE |
| aoqi@0 | 39 | // load the primitive field value into result (speculatively) |
| aoqi@0 | 40 | // load _safepoint_counter into new_counter |
| aoqi@0 | 41 | // IF (old_counter == new_counter) THEN |
| aoqi@0 | 42 | // no safepoint happened during the field access, return result |
| aoqi@0 | 43 | // ELSE |
| aoqi@0 | 44 | // a safepoint might have happened in-between, return jni_GetXXXField() |
| aoqi@0 | 45 | // ENDIF |
| aoqi@0 | 46 | // ENDIF |
| aoqi@0 | 47 | // |
| aoqi@0 | 48 | // LoadLoad membars to maintain the load order may be necessary |
| aoqi@0 | 49 | // for some platforms. |
| aoqi@0 | 50 | // |
| aoqi@0 | 51 | // The fast versions don't check for pending suspension request. |
| aoqi@0 | 52 | // This is fine since it's totally read-only and doesn't create new race. |
| aoqi@0 | 53 | // |
| aoqi@0 | 54 | // There is a hypothetical safepoint counter wraparound. But it's not |
| aoqi@0 | 55 | // a practical concern. |
| aoqi@0 | 56 | |
| aoqi@0 | 57 | class JNI_FastGetField : AllStatic { |
| aoqi@0 | 58 | private: |
| aoqi@0 | 59 | enum { LIST_CAPACITY = 40 }; // a conservative number for the number of |
| aoqi@0 | 60 | // speculative loads on all the platforms |
| aoqi@0 | 61 | static address speculative_load_pclist []; |
| aoqi@0 | 62 | static address slowcase_entry_pclist []; |
| aoqi@0 | 63 | static int count; |
| aoqi@0 | 64 | |
| aoqi@0 | 65 | static address generate_fast_get_int_field0(BasicType type); |
| aoqi@0 | 66 | static address generate_fast_get_float_field0(BasicType type); |
| aoqi@0 | 67 | |
| aoqi@0 | 68 | public: |
| aoqi@0 | 69 | #if defined(_WINDOWS) && !defined(_WIN64) |
| aoqi@0 | 70 | static GetBooleanField_t jni_fast_GetBooleanField_fp; |
| aoqi@0 | 71 | static GetByteField_t jni_fast_GetByteField_fp; |
| aoqi@0 | 72 | static GetCharField_t jni_fast_GetCharField_fp; |
| aoqi@0 | 73 | static GetShortField_t jni_fast_GetShortField_fp; |
| aoqi@0 | 74 | static GetIntField_t jni_fast_GetIntField_fp; |
| aoqi@0 | 75 | static GetLongField_t jni_fast_GetLongField_fp; |
| aoqi@0 | 76 | static GetFloatField_t jni_fast_GetFloatField_fp; |
| aoqi@0 | 77 | static GetDoubleField_t jni_fast_GetDoubleField_fp; |
| aoqi@0 | 78 | #endif |
| aoqi@0 | 79 | |
| aoqi@0 | 80 | static address generate_fast_get_boolean_field(); |
| aoqi@0 | 81 | static address generate_fast_get_byte_field(); |
| aoqi@0 | 82 | static address generate_fast_get_char_field(); |
| aoqi@0 | 83 | static address generate_fast_get_short_field(); |
| aoqi@0 | 84 | static address generate_fast_get_int_field(); |
| aoqi@0 | 85 | static address generate_fast_get_long_field(); |
| aoqi@0 | 86 | static address generate_fast_get_float_field(); |
| aoqi@0 | 87 | static address generate_fast_get_double_field(); |
| aoqi@0 | 88 | |
| aoqi@0 | 89 | // If pc is in speculative_load_pclist, return the corresponding |
| aoqi@0 | 90 | // slow case entry pc. Otherwise, return -1. |
| aoqi@0 | 91 | // This is used by signal/exception handler to handle such case: |
| aoqi@0 | 92 | // After an even safepoint counter is loaded and a fast field access |
| aoqi@0 | 93 | // is about to begin, a GC kicks in and shrinks the heap. Then the |
| aoqi@0 | 94 | // field access may fault. The signal/exception handler needs to |
| aoqi@0 | 95 | // return to the slow case. |
| aoqi@0 | 96 | // |
| aoqi@0 | 97 | // The GC may decide to temporarily stuff some bad values into handles, |
| aoqi@0 | 98 | // for example, for debugging purpose, in which case we need the mapping also. |
| aoqi@0 | 99 | static address find_slowcase_pc(address pc); |
| aoqi@0 | 100 | }; |
| aoqi@0 | 101 | |
| aoqi@0 | 102 | #endif // SHARE_VM_PRIMS_JNIFASTGETFIELD_HPP |
